Transmission brake



July 25,1939. -A. Y. DODGE TRANSMISSION BRAKE Filed April e, 19:58

Patented iul izs, 1939 UNITED". STATES- PATENT orFi-ea My invention relates to a rotation controlling construction; and more specifically to aclutch control for transmissions.

One of the objects of my invention is to provide .such a construction having an external actuating band to which 'arcuate gripping band means are secured, and means for definitely limiting the expanding movement of the actuating band so that, in its extreme expanded position it will be concentric with the rotatable member so that'the gripping bands carried thereby will be uniformly spaced throughout their extent with respect to-the gripping surface of the rotatable member. a

A further object of my invention is to provide such a construction in which a number of aren'- ate gripping band members are secured to the actuating band to move radially in and out therewith and in which at least one of said gripping band members can move circumferentially with respect to the actuating band and in which abutment means are provided for holding the gripping band member against any substantial circumfer .ential movement.

A further object of my invention is to provide a construction as indicated above, in which the resultant radial load imposed on the shaft or the supporting bearings (not shown)"is reduced to m further object of my invention is to provide a construction as indicated above,\in which the actuating band will move from a completely expanded position in which itis centered by the surrounding support to a positionin which the gripping bands are firmly applied regardless of variations in the movement required due to wear on the gripping band means. 1 1

\, While only an external contracting construe tion'is shown and described herein, it is apparent Lo that an internalexpanding construction might' tlon controlling construction substantially on the line of F162;

Fig. 2 is an axial section substantially line 2-2 of Fig. 1: and I r Fig. 3 is a section substantially on the line 3+8 ofFig. 1.

on the 1 ing band.

Referring to the drawing in detail, the con-r struction shown comprises a rotatable shaft I,

mobile or the like, a member 2 rotatable with the shaft and having an external cylindrical grip surface 3, a plurality of arcuate gripping band .members 4 and 4a (two being shown) surrounding the grip surface 3 and movable into and out of engagemen't therewith, a metal actuating band 5 surrounding the gripping band members 4 and 4a to which the gripping band members are secured so that contraction and expansion of the actuating,band moves the gripping band mem-,

bus into and out of engagement with respect to which may be part of a transmission for an autoagainst which the actuating band 5 expands and rests'when in its completely expanded position,

securing one end of the actuating band 5 against circumferential movement,-and actuating means 9 for effecting circumferential movement of the other end of the actuatingband to efiect the contracting and expanding movement of the actuat- The actuating means for the actuating band shown comprises a rock shaft Ill rockably mounted in a bearing'bushing ll screwed into the casing 1 and having a. crank pin l2 operating in a slot or groove l3 in a block secured to the movable end of the actuating band. The supporting and positioning ring 61s provided with a suitable opening-15 through which the block of the actuating band extends and in which it is movable. The positioning ring is-also provided with an opening'to snugly receive an anchorage block lfi-towhichone end of the actuating band 5 is secured and to which one end of the arcuate gripping member-4 also is securedfby means of rivets H. The supporting and positioning ring is also provided withan opening to receive an anchorage block l8 secured to the gripping band member by means of rivets 19 or the like. These rivets extend through slots 20 in the actuating band so that provision is thus made for some relative circumferential movement between the-gripping band member'- la and the actuating band. This'lost motion connection between the gripping band member la and the actuating band is provided because of the faet'that in its expanding -and contracting movement portions of the actuating band must hate some circumfen ential movement and in the circumferential mcve- Y ment the anchorage for the gripping band membermust not be or interfered with.

terial secured to-an arcuate Each gripping. band member may comprise an" arcuate member 2| made of table gripping maetal backing merriber ilin any suitable manner, the metal bacb ing membersbeing provided with the anchorage blocks l1 and' it for holding themlrgainst circumferential movement. Each of the metal backing members of the gripping members 22 may besecuredtothe actuatingbandiatatleastone point by means of rivets 23 or the like, the supp rting and positioning ring-6 being provided with suitableopening '2'1, to provide clearance for the heads of these rivets. The actuating band 5 is slotted circumferentially atflo, where rivets 23 intersect it, to allow free circumferential movement of band I.

In use it will beseen thatthe actuatingband '5 is limited in its expanding-movement by engagement with the inner cylindrical surfaceoi the supporting and podtioning ring C, and that the actuating band 5 is thus centered with respect to theaxis ofthe shaft and drum. This p0- sitioning band'thus definitely limits the expanding movement of the actuating band-and positions and centers it with respect to the axis of the shaft and the rotatable drum. g

' Assuming that the rotatable drum is rotating in the direction of the arrow AinFlg. 1 and that the rockshaft i2 is rotated to move the crank] pin and block member'upwardly, this will cause the actuating band 5 to contract and to move rathough the gr pmband dially inwardly, causing the grinn hand members I and la to snugly engage the grip surface of the rotatable drum 2. As each of the gripping members is of considerableextent, there will be .ping band members 4 and la to bemoved into snug engagement with the grip surface even membersareconsiderr ablyworn. w

Itwillbeseenthatinthe dis-' I closed the supportingand positioning ring 0 den- I the grip band members.

nitely positionstheactuatingbandIiniisex-r treme expanded position so that it is concentric withthe rotatable-member 2 so that the gripping band members land will then bejuniformly spaced throughout their extent w'ithrespect to thegrip surface I of the rotatable manberrthat the gripping-band members are held against-circumferential movement without interfering with the proper action of the actuating band i; that the expanding andcontracting movement of the. actuating band is reduced to 'a; minimum consistcut with good practice; and that the achiating band will move from itscompletely expanded sitiontoa liosltioninwhiclithegrlp flngband members are firmly applied regardleof variations in the movement required due to wear on Itwill be seenthat the radial forces mulling bo h m t 's pnplrins forces and the an.- shorage loads are because of tbe'two anchorage blocks It and II located at diametrically opposite points which handle th gripping load and because of the full wrap which handles the grip-applying forces. -A s a consequence of this counterbalancing, the radial forces acting on the rotatable member will be reduced sulistantially to zero.

Further modifications will be apparent to those skilled in the art, and it is desired, therefore, that the invention be limited only by the prior art and the scope of the appended claims.

Having thus" described my invention, what I claim'and desire to secure by Letters Patent is:

1. A rotation controlling construction comprising a rotatable member having an external cylindrical grip surface, a plurality of arcuate-grip'ping band members surrounding said grip surface spaced circumferentially from each other and engageable successively with the same portion or said grip surface and movable into and out of en'- gagement therewith, an actuating bandv surrounding said gripping band members to which said gripping band members are secured so that contraction and expansion of the actuating band will move the gripping band members into arid j out of engagement with respect to said grip sur- "cylindrical grip surface, a pluralityof arcuate gripping band members surrounding said grip and movable into and out of engagement therewith, an actuating band surrounding said S pping band members to which said gripping band members are secured so that contraction and expansion of the actuating band will move the gripping band members into and out of engagement with respect to said grip surface, means for anchoring one end of said actuating band against circumferential movement, means for moving the other end of the actuating band circumferentially .to effect contracting and expanding movement of the actuating band, the connection or one end of one of said grlpping band members with the' actuating band enabling circumferential movement of the gripping band member with respect to the actuating band,

' means for anchoring said end ofsaid gripping band member againstv circumferential movement an anchorage member secured to said fl pping band member extending through said actuating band,.-and a fixed abutment engaged .by said anchorage member.

v 3. A rotation "controlling construction comprising a rotatable member having an external cylindricalgrip surface, a plurality'of arcuate fl pping band members surrounding said grip surface and movable into and out of engagement therewith, an actuating band surrounding said ripping band members to which said gripping band members are secured to prevent relative radial movement between said actuating band and'gripping band so that contraction and ex-' pension of the actuating band will move the gripping band members into and out of engagement with respect to said grip surface, meansior anchoring one end of said actuating hand against circumferential movement, means for'moving the other end ofthe actuating band circumferentially to .eflect contracting and expanding movement of the actuatingband, the connection of one end of one of said gripping band members with the. actuatingband enabling circumferential movement of the gripping band member with respect to, the actuating band, and means fo'ranchoring said end of. said gripping band member against cirrmmferem tlal'movement, said construction having provisions whereby the resultant of combined forces acting on said rotatable member counterbalance. each other and are reduced substantially to zero 4. A rotation controlling construction com- 'prising a rotatable member having an' external connection'of one end of one of said gripping bandmembers with the actuating band enabling circumferential movement of the gripping band member with-respect to the actuating .band, means for. anchoring said end of said gripping band member against circumferential movement comprising an anchorage member secured to said gripping band member extending through said actuating band, and an abutment engaged by said anchorage member, said construction having provisions whereby the radial" forces acting on said rotatable member counterbalance each other and are reduced substantially to zero.

5; A rotation controlling construction comprising a rotatable member having an external cylindrical grip surface, actuating gripping band means surrounding said grip surface and movable into and out of engagement therewith, an'actuating band surrounding said gripping band means to which said gripping band means are secured so that contraction and expansion of said actuating band moves the gripping band means into and out of engagement with said cylindrical grip surface, a cylindrical supporting .sur-face surrounding. said actuating band for centering said actuating band and gripping band, means when the actuating band is in expanded; position,

and meanswhereby said'actuatlng band may be contracted and expanded; said construction hav ing provisions whereby the radial'forces actingon said rotatable member counterbalance each' other and are reduced substantially to-zero. a 6. A transmission; brake comprising a ,fixed,- accurately formed, closely-surrounding"ring; an actuating band lying therein, a-plurality of metal brake band segments with friction material secured thereto. lying inside said actuating ,band,g

one. end of each brake band, -said anchoragemeans cooperating with the fixed outer ring'to.

prevent circumferential movement of the brake bands but permitting circumferential movementof the actuating band, separate means for attacking brake bands to theactuatin band -.pe initting relative circumferentialmovement but wi t an external cylindrical brakesurface lying inside said friction material, an anchorage means at Y preventing relative radial movement therebetween, and means forexpanding said actuating band into the fixed ring and for contracting the actuating band to force the brake hands into engagement with the brake surface.

7. A transmission brake. comprising a fixed, accurately formed, closely-surrounding ring, an actuating'band lying therein, a plurality of metal brake band segments with friction material secured thereto lying inside said, actuating band,

an external cylindrical brake surface lying inside said friction material, an anchorage means atone end of each br'ake band, said anchorage means cooperating with the fixed outer ring to prevent circumferential movement of the brake bands but permitting circumferential movement of the actuating band, separate means for attaching brake bands to the actuating band permitting relative circumferential movement but preventing relative radial movement therebetween, and means vfor expanding said actuating band into the fixed .ring and for contracting the. actuating band to force the brake bands into engagement-with -the brake surface, saidactuating means and anchorage means being oppositely located so that the actions and reactions neutralize, thereby im- 8.- A transmission brake'comprising a fixed, ac-

curately formed, closely-surrounding ring, an

actuating band lying therein, a plurality of metal brake band segments with friction material secured thereto lying inside said actuating band, an external cylindrical brake surface lying inside said friction materialsan anchorage means at one end of each brake band, said anchorage posing no appreciable ,load on the center shaft.

means cooperating with the fixed outer ring to -prevent circumferential movement of the actuating band, separate means for attaching brake bands to the actuating band permitting relative circumferential movement but preventing relative radial movement therebetween, and means for expanding said actuating band into the fixed ring and for contractingthe actuating band to force the brake bands. into engagement with the brake surface, said brake bandsbeing anchored at their trailing ends to. permit a partial wrapping action on each brake band segment.

9. A transmission brake comprising a fixed, ac-

curately formed, closely-surrounding ring, an

actuating band lying therein, a plurality of metal brake band-segments with friction material secured thereto lying inside said actuating band, an external cylindrical brake surf ace lying inside sa1d,

friction material, an anchorage means atone end' of each brake band, said anchorage means cooperating with the fixed outer ring to prevent circumferential movement of the-brake bands but permitting circumferential movement of the actuating band, separate means for attaching, brake bands to the actuating band permitting Irlative circumferential movement but preventing relative radial 1 movement therebetween, and

,means for expanding said actuating band intothe'fixedring and for contracting the actuating b d to force the brake 'bandsinto engagement the brake surface, said brake band segments being so constructed that they may be assembled end for end into their respective places, thus making the'clutch brake suitable for right-hand,

left-hand o'r'both right-handzand'left-hand rotions by merely altering the assembly. 1 .92

A, transmission brake comprising 'a brak having-an external cylindrical grip surface aumul tiplieity of brake bands surrounding said gr surface, spaced circumferentially from each I- r flexiblebrakistraps 1e saidflexiblebrake straps to '5' movement the other and. engageable-s'uccessively with the same portion of said grip surface, an actuating band surrounding the brake buds, means'connecting said' brake bands to said actuating band so that 5 contraction and nof said actuating band wilimove said brake hands into and out of en-' gagement with respect to said grip surface and will enable relative circumferential movement of said brake bands with respect to said actuating o band, anchorage and application means for the actuating band located so that the force of actuation and. the reaction force on its anchor will substantially cancel each other to produce no shaft load, and anchors for thebrake bands 10- cated to carry equal loads and circumferentially spaced around the brakedrum so that the vector sum of the tangential loads due to torqueoounteract each other load.

Y closely-fitting, fixed ring, a revolvable drum to be braked, amultiplieity of brake bands, means for expanding the brake bands tightly into the fixedring to insure definite clearance between the band g and drum and for contracting the band toward the revolvable drum to brake the drum comprising an actuating band surrounding the brake band, and anchorage andapplication means for the actuating band located so that the force of m actuation and the reaction force on its anchor will substantially cancel each other toproduce no shaft load, the anchors of the brake bands being located to carry-equal loads and arranged ..-the circleso that the vector sum of the tangenas tial loads due to torque counteract each other to cause substantially no.shaft load. I 12. A brake'constmction comprising a r,otat'- able member'having a cylindrical grip surface, a support having a continuous arcuate supporting do and adjacent saidgrip surfaceand coaxial therewith, a plurality of arcuate flexible brake straps engageable and abie with respect to said cylindricalgrip surface, I a flexible actuating band between said flexible 1| brake straps and said continuous arcuate sup porting surface; means for securing each of.jsaid flexible straps to Said flexible for efl 5 betweenthe endsof said actuating band in one j directionto force the straps snugly the cylindricalgrip in the II opposite'direction'to force the flexible actuating band snugly against the continuous arcuate sup-.

Porting and niteclear'ance between the flexible and the cylindrical grip surface.

I 13. A brake construction arcuate supporting and surface adjacent said face and coaxial, I aplurality;

- gageable with'remeetto said face,-a flexible actinting band ible brake straps and said' relative radial movement between .said, straps-and actuating band, and, mcans 'for effecting relative circumferential v tocausesubs tia llyno shaft- 11.- A ton brake comprising an outer,

g V actuating- 5 band at a plurality of circumferentiallyspaced points to prevent relative radial movement. so tween saidstraps and actuating band,,and means relative. movement to insure a defl-.

. 4 mmpr sins {rotatable member having a cylindrical grip'surface.- a 1 anddis'en-.

lindrical srinlllrsaid flex- -supporting surface, means for eachof T said flexibleactuak band at ajphirslityf of.

e points to prevent ends.

band in one direction to force the flexible brab straps snugly against the cylindrical grip surface and in the opposite direction to force the flexible actuating band snugly against the continuous arcuate supporting and positioning surface to insure a definite clearance between the flexible brake'straps-and the cylindrical grip surface, tlm securing means between the brake straps and the actuating band including lost motion means whereby a portion of the strap 'may have a cirv cumferential movement with respect to the actuatingband.

14. A brake construction comprising a rotat-; able member having a cylindrical grip surface, a plurality of arcuate flexible brake straps engageable and disengageable with respectto said cylindrical grip surface, a flexible actuating band bearing on said flexible brake stra means for securing each of said flexible brake s raps to said flexible actuating band at a plurality of circumferentially spaced points to 'prevent relative -movement therebetween, and means for effecting 7 ends of'said actuating band to force the flexible brake straps snugly against the'cyllndrical grip surface, the securing means. between the brake straps and the actuating band including lost a motion means whereby a portion of the strap may have a circumferential movement with res spect'to' the actuating band.

porting surface, means fgrsecuring each of said 40 flexible brake straps to said flexible actuating band'at a. plurality of circumferentially, spaced points to prevent relativejradial movement between said straps and actuating band, means for effecting relative-circumferentialmovement between the ends ofisaid actuating-bandinone di- .rection to force the flexible brake straps snugly against the cylindrical grip surface-and, inthe opposite direction to force the flexible actuating porting and positioning surface to insure a, definite clearance between the flexible brake straps and the cylindrical grip surface, the securing means between the brake straps and the actuating bandlost motionmeans whereby a portion of including the strap y have "a circumferential movement for holding said flexible brake band strapsagainst I member whileenabling said lostmotion circumferential movement;

said flexible brake straps, means for securlngeaeh cf-said flexible-brakestransltb said flexible;actupoints to prevent relative movement therebetween, means for .-relative circumferential movement between the said actuatingband to force the flexible straps snu8 y flsainst the cylindrical gripsurface, the serelative circumferential movement between the 15. A brake construction comphising a rotata-. v bie member having-a cylindrical grip surface, a

band snugly against the continuous arcuate sup- 5 with/respec to the actuating band, andv means circumferential movement ,withthe rotatable 1Q. A, brake construction comprising a rotatable member having a. cylindrical gripsurface'a plu-- rality of arcuate flexible brake straps .engageable r and disengageable with respect to said cylindrical cs grip surface, a flexible actuating band bearing on atin'g band'at a pluralityof circumferentially e ins between straps j.

actuating band including lost motion means whereby a portion of the'strap may have a circumferential movement with respect to the actuating band, and means for holding said flexible brake band straps against circumferential movement'with the rotatable member while enabling said lost motion circumferenttal movement.

1'1. A brake construction comprising a rotatable member having a cylindrical grip surface, a support having a continuous arcuate supporting and positioning surface adjacent said grip surface and:

coaxial therewith, a plurality of arcuate flexible vbrake straps engageable and disengageable with respect to said cylindrical grip surface, a flexible actuating band between said flexible'brake straps and said continuous arcuate supporting surface,

surface and coaxial therewith, a plurality of arcu-' means for securing each of said flexible brake a straps to said flexible actuating band at a plurality of circumferentially spaced points to prevent relative radial movement between said straps and actuating band, means for effecting relative circumferential movement between the ends of said actuating band in one direction to force the flexible brake strapssnugly against the cylindrical grip surface and in the opposite direction to force the flexible actuating band snugly against ate flexible brake straps engageable and disengageable with respect to said cylindrical grip surface, a flexible actuating band between said flexible brake straps and said continuous arcuate supporting surface, means for securing eachof said flexible brake straps to said flexible actuating band at a plurality of circumferentially spaced points to prevent relative radial movement between said straps and actuating band, and means for, effecting relative circumferential movement between the ends of said actuating band in one direction to force the flexible brake straps snugly against the cylindrical grip surface and in'the opposite direction to force the flexible actuating bandsnugly against the continuous arcuate supporting and positioning surface to insure a definite clearance between the flexible brake straps and the cylindrical grip surface. Y

19. A brake construction comprising a rotatable member having a'cylindrical external grip sur..-'

face, a support having a continuous arcuate sup-- portingandpositioning surface adjacent said grip surface and coaxial therewith, a plurality of arcuate flexible brake straps engageable and disengageable with respect to said cylindrical grip surface, a flexible actuating band between said flexible brake straps and said continuous arcuate supporting surface, means for securing each of said flexible brake straps to said flexible actuating band at a plurality of circumferentially spaced points to prevent relative radial movement between said straps and actuating band, means for effecting relative circumferential movement between the ends of said actuating band in one direction to force-the flexible brake straps snugly against the cylindrical grip surface'and in the opposite direction'to force the flexible actuating band snugly-against the continuous arcuate supporting and positioning surface to insure a definite clearance between the flexible brake straps and the cylindrical grip surface, the securing means between the brake straps and the actuating band including lost motion means whereby a portion of the strap may have a, circumferential movement withrespect to the actuating band, and means for holding said flexible brake band straps against circumferential 'movement with the rotatable member while enabling said lost motion circumferential movement.

. 20. A brake construction comprising a rotatable member having a cylindrical grip surface, a support having a continuous arcuate supporting and positioning surface adjacent said grip surface and coaxial therewith, a plurality of arcuate flexible brake straps engageable and disengageable with respect to said cylindrical grip surface, a flexible actuating band between said flexible brake straps and said continuous arcuate supporting surface, means for securing each of said flexible brake straps to said flexible actuating band at aplurality of circumferentially spaced points to prevent relative radial movement between said straps and actuating band, means for [effecting relative circumferential movement between the ends of said actuating band in one direction to force the flexible brake straps snugly against the cylindrical grip surface and in the opposite direction to force the flexible actuating band snugly against the continuous arcuate-supporting and positioning surface to insure a definite clearance between the flexible brake straps and the cylin- *di'lcal grip surface, the securing means between the brake straps and the actuating band including 10st motion means whereby a portion of the strap may have a circumferential movement with respect to the actuating band, and means for holding said flexible brake band straps against circumferential movement with the rotatablesmember while enabling s'aid lost motion circumferential movement, comprising a holding member extending through said flexible actuating band;

ADIEL Y. DODGE. 

